Hydroquinones

ABSTRACT

New hydroquinones have the formula:    &lt;IMAGE&gt;  I  wherein p is 1 or 2 and q is 0 or 1, provided that p+q is 1 or 2; R is a residue of formula:    &lt;IMAGE&gt; II  wherein Q is (i) -OX or (ii) -PO(OR11)((O)xR11); and salts thereof with organic or inorganic acid bases. The groups X and R11 and x are defined hereinafter. The compounds of formula I are useful as stabilisers in photographic materials.

This is a continuation-in-part of application Ser. No. 628073, filed July 5th, 1984 (now abandoned), which application is a division of application Ser. No. 389,992, filed June 18, 1982 (now U.S. Pat. No. 4,484,000).

The present invention relates to new hydroquinones and a process for their preparation.

According to the present invention, there are provided novel hydroquinones having the formula: ##STR3## where p is 1 or 2 and q is 0 or 1, provided that p+q is 1 or 2; R is a residue of formula ##STR4## wherein Q is selected from the residues:

(i) --COZR₄ wherein Z is O or NR₅, and R₄ independently is H, a straight or branched chain alkyl having from 1 to 20 carbon atoms, optionally interrupted by 1 to five oxygen atoms, and optionally substituted by a group OR₆ wherein R₆ is C₁ -C₁₂ alkyl, C₃ -C₁₂ cycloalkyl, straight or branch C₃ -C₂₀ alkenyl, C₆ -C₁₀ aryl optionally substituted by one or two C₁ -C₄ alkyl groups of C₇ -C₁₃ aralkyl, or R₄ a straight or branched chain alkenyl group having from 3 to 20 carbon atoms or a cycloalkyl group having from 3 to 12 carbon atoms; an aryl group having from 6 to 10 carbon atoms optionally substituted by a C₁ -C₄ alkyl group; or an aralkyl group having from 7 to 13 carbons atoms; a 5 or 6 membered heterocycle containing an oxygen atom, and optionally substituted by one or two C₁ -C₄ straight- or branch chain alkyl groups; or methyl substituted by a 5 or 6 membered heterocycle containing a oxygen atom and optionally substituted by one or two C₁ -C₄ straight- or branch chain alkyl groups; and when Z is --NR₅, R₅ is hydrogen or a straight or branched chain alkyl group having from 1 to 20 carbon atoms, or R₄ and R₅ together with the nitrogen atom to which they are each bonded may form a 5 or 6 membered heterocyclic ring, optionally substituted by one or two C₁ -C₄ alkyl groups;

(ii) --OX wherein X is R₅ or --COR₇, wherein R₅ has its previous significance, R₇ is H or a straight- or branch chain alkyl group having from 1 to 20 carbon atoms, a straight- or branch chain alkenyl having from 3 to 20 carbon atoms, a C₃ -C₁₂ cycloalkyl group, a C₇ -C₁₃ aralkyl group, or a C₆ -C₁₀ aryl group, optionally substituted by one or two C₁ -C₄ alkyl groups;

(iii) --NR₈ R₉ wherein R₈ is H or a straight- or branched chain alkyl group having from 1 to 12 carbon atoms and R₉ is H, a straight- or branched chain alkyl group having 1 to 12 carbon atoms, or an acyl group of formula --COR₇ wherein R₇ has its previous significance, or R₈ and R₉, together with the nitrogen atom to which they are each bonded, form a 5- or 6-membered ring, optionally substituted by one or two C₁ -C₄ alkyl groups;

(iv) --PO(OR₁₀)([O])_(x) R₁₁) wherein x is 0 or 1, and when x is 1 R₁₀ and R₁₁ are the same or different and each is H or a straight or branched chain alkyl group having from 1 to 20 carbon atoms: or R₁₀ and R₁₁ may be linked together to form a C₂ -C₃ alkylene chain optionally substituted by one or more C₁ -C₂₀ alkyl groups; and when x is 0, R₁₀ is hydrogen or a straight- or branched chain alkyl group having from 1 to 20 carbon atoms and R₁₁ is a C₁ -C₅ straight chain alkyl group;

(v) --SO₂ R₁₂ wherein R₁₂ is OH, Cl or --NR₅ R₇ wherein R₅ and R₇ have their previous significance; provided that, when R₁₂ is OH, then R₁ is a residue of formula II; and

(vi) CN;

n is an integer from 1 to 20; k is 1 or 2; R₂ and R₃ are the same or different and each is straight or branched chain alkyl group having from 1 to 5 carbon atoms and, when Q is --CO₂ R₄, either R₂ or R₃ is optionally substituted by a --CO₂ R₄ group, the R₄ groups being independent, or R₂ or R₃ may be so linked to the residue C_(n) H_(2n+1-k) that there is formed a C₅ -C₁₂ cycloalkylene residue substituted by the group --(CO₂ R₄)_(k), the R₄ groups being independent, wherein R₄ and k have their previous significance; R₁ is C₁ -C₈ straight- or branched chain alkyl, or a residue of formula II as hereinbefore defined, and when R₁ is a residue of formula II, then R₁ and R may be the same or different; and salts thereof with organic or inorganic acids and bases.

When the group R₁ is a C₁ -C₈ straight- or branched chain alkyl group it may be, for example, a methyl, ethyl, n-propyl, isopropyl, n-butyl, iso-butyl, t-butyl, t-amyl, or 1,1,3,3-tetramethylbutyl.

When the group R₂ or R₃ is a C₁ -C₅ straight or branched chain alkyl group it may be, for example, a methyl, ethyl, n-propyl, iso-propyl , n-butyl, sec-butyl, n-pentyl or neopentyl group.

When the group R₄ is a C₁ -C₂₀ straight or branched chain alkyl group optionally interrupted by one to 5 oxygen atoms it may be, for example, a methyl, ethyl, 2-methoxyethyl, 2-ethoxyethyl, 2-n-propoxyethyl, 2-n-butoxyethyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, n-dodecyl, n-tetradecyl, n-hexadecyl, n-octadecyl, n-eicosyl, --(C₂ H₄ O)₂ CH₃, --(C₂ H₄ O)₃ CH₃, --(C₂ H₄ O)₄ CH₃ or --(C₂ H₄ O)₅ CH₃ group.

When R₄, R₆ or R₇ is a C₃ -C₂₀ straight or branched chain alkenyl group, it may be for example, a prop-2-enyl, n-but-2-enyl, 2-methylprop-2-enyl, n-pent-2-enyl, n-hex-2-enyl, n-hexa-2,4-dienyl, n-dec-10-enyl, or n-eicos-2-enyl group.

When the group R₄, R₆ or R⁷ is a C₃ -C₁₂ cycloalkyl group, it may be, for example, a cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cylooctyl, cyclodecyl, adamantyl, or cyclododecyl group. When the group R₄, R₆ or R₇ is a C₇ -C₁₃ aralkyl group it may be, for example, a benzyl, phenylethyl, benzhydryl, or naphthylmethyl group.

When the group R₄, R₆ or R₇ is a C₆ -C₁₀ aryl group optionally substituted by one or two C₁ -C₄ straight or branched chain alkyl groups, it may be, a phenyl, tolyl, xylyl, cumyl, butylphenyl or naphthyl group.

When the group R₄ is a 5- or 6-membered heterocycle containing oxygen, and optionally substituted by one or two straight- or branch chain C₁ -C₄ alkyl groups, it may be, for example, tetrahydrofuran-3-yl, tetrahydropyran-4-yl or 2,6-dimethyl-tetrahydropyran-4-yl. When the group R₄ is methyl substituted by a 5- or 6-membered heterocycle containing an oxygen atom, and optionally substituted by one or two straight- or branch chain C₁ -C₄ alkyl groups, it may be, for example, furfuryl, tetrahydrofurfuryl or tetrahydropyran-2-yl-methyl.

When the group R₈ and R₉ is a C₁ -C₁₂ straight or branched chain alkyl group it may be for example, a methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl group, t-amyl, 1,1,3,3-tetramethylbutyl, n-hexyl, n-nonyl, n-decyl or n-dodecyl.

When the groups R₄ and R₅, and the groups R₈ and R₉, together with the nitrogen atom to which they are bonded form a 5- or 6-membered heterocyclic ring, optionally substituted by one or two C₁ -C₄ alkyl groups, this ring may be a pyrrolidine, piperidine, morpholine or a 2,5-dimethyl morpholine ring.

When the groups R₅, R₇, R₁₀ or R₁₁ are C₁ -C₂₀ straight or branched chain alkyl they may be the same or different and may be methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, n-dodecyl, n-tetradecyl, n-hexadecyl, n-octadecyl, or n-eicosyl groups.

When the groups R₁₀ and R₁₁ are linked to form a C₂ or C₃ methylene chain optionally substituted by one or more C₁ -C₂₀ alkyl chain, they may be for example --CH₂ CH₂ --, --CH₂ --CH₂ --CH₂ --, --CH₂ CH(CH₃)--, --CH₂ CH(C₂ H₅)--, --CH₂ CH(C₂₀ H₄₁)--, --CH(CH₃)CH(CH₃)--, --CH--(CH₃)C(CH₃)₂ --, --C(CH₃)₂ C(CH₃)₂ --, --CH₂ CH₂ --C(CH₃)₂ --, or CH(CH₃)CH₂ CH(CH₃)-- groups.

Examples of salts wherein Q is an acidic group --COOH include salts with alkali and alkaline earth metals and amines and, where Q is a NR₈ R₉ group, salts with organic and inorganic acids for example, hydrochloric, sulphuric, para-toluene-sulphonic and oxalic acids.

In one preferred embodiment, the groups R and R₁ are bonded in the 2- and 5-positions, respectively, in the hydroquinones of formula I.

More preferred compounds of the invention are those having the formula III: ##STR5## wherein R₂, R₃, n, k and Q have their previous significance and R₁ is a group of formula II, as hereinbefore defined, or is a group of formula IV: ##STR6## as well as salts thereof.

Further preferred compounds of formula III are those wherein R₁ is a group of formula II or IV, Q is --COZR₄ or --OR₅ wherein Z, R₄ and R₅ have their previous significance, R₂ and R₃, independently, are methyl, ethyl, n-propyl, isopropyl, or neopentyl, or either R₂ or R₃ is optionally substituted by a group --COOR₄ in which R₄ has its previous significance, or R₂ or R₃ may be so linked to the residue C_(n) H_(2n+1-k) that there is formed a cycloalkylene residue having 5 to 8 carbon atoms which is substituted by --COOR₄, and n and k have their previous significance; as well as salts of these compounds.

More particularly preferred are compounds of formula III in which k is 1, R₁ is a group of formula II or IV, Q is --COZR₄ or --OR₅, n is an integer from 1 to 10, R₂ and R₃, independently, are methyl, ethyl or neopentyl, or one of R₂ and R₃, may be so linked to the residue C_(n) H_(2n+1-k) that there is formed a cyclohexylene residue which is substituted by --COOR₄, R₄ is hydrogen, C₁₋₂₀ -alkyl (optionally interrupted by 1, 2 or 3 oxygen atoms and/or optionally substituted by --OR₆ wherein R₆ is cyclopentyl, cyclohexyl, cyclooctyl, C₃₋₁₀ alkenyl, phenyl, benzyl, phenethyl, benzhydryl or naphthylmethyl) or R₄ is C₃₋₁₅ alkenyl, phenyl optionally substituted by 1 or 2 C₁₋₄ alkyl groups, benzyl, phenethyl, cyclopentyl, cyclohexyl or a 5- or 6-membered heterocyclic ring containing an oxygen atom, which ring is optionally substituted by 1 or 2 C₁₋₄ -alkyl groups and R₅ have their previous significance, or R₄ and R₅, together with the nitrogen atom to which they are each bonded, may form a 5- or 6-membered heterocyclic ring, optionally substituted by one or two C₁₋₄ alkyl groups; as well as salts of these compounds.

Still further preferred compounds of formula III are those wherein k is 1, R₁ is a group of formula II or IV, Q is --COZR₄ or --OR₄, Z has its previous significance, n is an integer from 1 to 10, R₂ and R₃, independently, are methyl, ethyl or neopentyl or one of R₂ and R₃ may be so linked to the residue --C_(n) H_(2n+1-k) that there is formed a cyclohexylene residue which is substituted by --COOR₄, R₄ is hydrogen, C₁₋₂₀ -alkyl (optionally interrupted by 1 or 2 oxygen atoms and/or optionally substituted by cyclohexyloxy, C_(3-C) ₁₀ -alkenyloxy, phenoxy or benzyloxy) or R₄ is C₃₋₁₅ alkenyl, phenyl, benzyl, phenethyl, cyclopentyl, cyclohexyl, or 5- or 6-membered heterocyclic ring containing an oxygen atom, or methyl substituted by a 5- or 6-membered heterocyclic ring containing an oxygen atom and is, especially, C₁₋₁₆ alkyl (optionally interrupted by an oxygen atom or optionally substituted by phenoxy) or R₄ is tetrahydrofuran-3-yl, tetrahydrofuran-4-yl or tetrahydrofurfuryl and R₅ is hydrogen or C₁₋₁₅ -alkyl, or R₄ and R₅, together with the nitrogen atom to which they are each bonded, may form a 5- or 6-membered heterocyclic ring optionally substituted by one or two C₁₋₄ -alkyl groups; as well as salts thereof.

Particularly preferred are compounds of formula III wherein k is 1, R₁ is a group of formula II or IV, Q is --COZR₄ or --OR₅ wherein Z has its previous significance, n is an integer from 1 to 3, R₂ and R₃ are each methyl or neopentyl, R₄ is hydrogen, C₁₋₁₆ alkyl (optionally interrupted by an oxygen atom or optionally substituted by phenoxy) or R₄ is phenyl, benzyl or tetrahydrofuran-3-yl, R₅ is hydrogen or C₁₋₁₅ alkyl, or R₄ and R₅, together with the nitrogen atom to which they are each bonded, may form a 5- or 6-membered heterocyclic ring optionally substituted by 1 or 2 C₁₋₄ -alkyl groups, provided that, when Q is --OR₅, R₅ is, in particular, C₁₋₈ alkyl; as well as salts of these compounds.

In compounds of formula I wherein O is --OR₅ and n is 1 to 20, the most preferred compounds are those wherein n is 2 to 20.

Non-limiting examples of compounds of Formula I include:

Methyl 3-(2',5'-dihydroxyphenyl)-3-methyl-butyrate

n-Hexyl 3-(2',5'-dihydroxyphenyl)-3-methyl-butyrate

n-Hexyl 3-(4'-t-butyl-2',5'-dihydroxyphenyl)-3-methyl-butyrate

n-Dodecyl 3-(4'-t-butyl-2',5'-dihydroxyphenyl)-3-methyl-butyrate

2',5'-Bis-(3-methoxycarbonyl-2-methylprop-2-yl)-hydroquinone

2',5'-Bis-(3-n-hexyloxycarbonyl-2-methylprop-2-yl)-hydroquinone

2',5'-Bis-(3-n-dodecyloxycarbonyl-2-methylprop-2-yl)-hydroquinone

1-(2',5'-Dihydroxyphenyl)-4-methoxycarbonyl-1-methyl-cyclohexane

1-(2',5'-Dihydroxyphenyl)-4-n-hexyloxycarbonyl-1-methyl-cyclohexane

2',5'-Bis-(4-methoxycarbonyl-1-methyl-cyclohex-1-yl)-hydroquinone

2',5'-Bis-(4-n-hexyloxycarbonyl-1-methyl-cyclohex-1-yl)-hydroquinone

2'-(5-Methoxycarbonyl-2-methyl-pent-2-yl)-hydroquinone

2'-(5-n-Hexyloxycarbonyl-2-methyl-pent-2-yl)-hydroquinone

2'-(5-n-Hexyloxycarbonyl-2-methyl-pent-2-yl)-5'-methyl-hydroquinone

2'-(5-n-Hexyloxycarbonyl-2-methyl-pent-2-yl)-6'-methyl-hydroquinone

2'-(5-Methoxycarbonyl-2-methyl-pent-2-yl)-5'-t-butyl-hydroquinone

2'-(5-n-Hexyloxycarbonyl-2-methyl-pent-2-yl)-5'-t-butyl-hydroquinone

2'-(5-n-Dodecyloxycarbonyl-2-methyl-pent-2-yl)-5'-t-butyl-hydroquinone

2'-(5-Methoxycarbonyl-2-methyl-pent-2-yl)-5'-(1,1,3,3-tetramethylbutyl)-hydroquinone

2',5'-Bis-(5-methoxycarbonyl-2-methyl-pent-2-yl)-hydroquinone

2',5'-Bis-(5-ethoxycarbonyl-2-methyl-pent-2-yl)-hydroquinone

2',5'-Bis-(5-n-propyloxycarbonyl-2-methyl-pent-2-yl)-hydroquinone

2'-(5-n-Hexyloxycarbonyl-2-methyl-pent-2-yl)-5'-(3-n-hexyloxycarbonyl-2-methyl-prop-2-yl)-hydroquinone

2'-(5-n-Hexyloxycarbonyl-2-methylpent-2-yl)-5'-(3-n-octyloxycarbonyl-2-methyl-prop-2-yl)-hydroquinone

2',5'-Bis-(5-iso-propyloxycarbonyl-2-methyl-pent-2-yl)-hydroquinone

2',5'-Bis-(5-n-butyloxycarbonyl-2-methyl-pent-2-yl)-hydroquinone

2',5'-Bis-(5-iso-butyloxycarbonyl-2-methyl-pent-2-yl)-hydroquinone

2',5'-Bis-(5-n-pentyloxycarbonyl-2-methyl-pent-2-yl)-hydroquinone

2',5'-Bis-(5-iso-pentyloxycarbonyl-2-methyl-pent-2-yl)-hydroquinone

2',5'-Bis-(5-n-hexyloxycarbonyl-2-methyl-pent-2-yl)-hydroquinone

2',5'-Bis-(5-n-heptyloxycarbonyl-2-methyl-pent-2-yl)-hydroquinone

2',5'-Bis-(5-cyclohexyloxycarbonyl-2-methyl-pent-2-yl)-hydroquinone

2',5'-Bis-(5-octyloxycarbonl-2-methyl-pent-2-yl)-hydroquinone

2',5'-Bis-[5-(2"-ethylhexyloxycarbonyl)-2-methyl-pent-2-yl]-hydroquinone

2',5'-Bis-(5-n-dodecyloxycarbonyl-2-methyl-pent-2-yl)-hydroquinone

2',5'-Bis-(5-n-hexadecyloxycarbonyl-2-methyl-pent-2-yl)-hydroquinone

2',5'-Bis-[5-(2'-methoxyethoxycarbonyl)-2-methyl-pent-2-yl)]-hydroquinone

2',5'-Bis-[5-(2"-n-butoxyethoxycarbonyl)-2-methyl-pent-2-yl)]-hydroquinone

2',5'-Bis-[5-(2"-cyclohexyloxyethoxycarbonyl)-2-methyl-pent-2-yl)]-hydroquinone

2',5'-Bis-[5-(2"-allyloxyethoxycarbonyl)-2-methyl-pent-2-yl)]-hydroquinone 2',5'-Bis-[5-(2'-benzyloxyethoxycarbonyl)-2-methyl-pent-2-yl)]-hydroquinone

2',5'-Bis-[5-(2"-phenoxyethoxycarbonyl)-2-methyl-pent-2-yl]-hydroquinone

2',5'-Bis-(5-phenoxycarbonyl-2-methyl-pent-2-yl)-hydroquinone

2',5'-Bis-(5-benzyloxycarbonyl-2-methyl-pent-2-yl)-hydroquinone

2',5'-Bis-(5-tetrahydrofurfuryloxycarbonyl-2-methyl-pent-2-yl)-hydroquinone

2',5'-Bis-(5-furfuryloxycarbonyl-2-methyl-pent-2-yl)-hydroquinone

2',5'-Bis-(5-tetrahydropyran-4-yloxycarbonyl-2-methyl-pent-2-yl)-hydroquinone

2'-(5-n-Hexyloxycarbonyl-2-methyl-pent-2-yl)-5'-(5-methoxycarbonyl-2-methyl-pent-2-yl)-hydroquinone

2',5'-Bis-(5-carboxy-2-methylpent-2-yl)-hydroquinone and its sodium salt

2',5'-Bis-(5-carbamoyl-2-methylpent-2-yl)-hydroquinone

2',5'-Bis-(5-N-n-butylcarbamoyl-2-methylpent-2-yl)-hydroquinone

2',5'-Bis-(5-N,N-dimethylcarbamoyl-2-methylpent-2-yl)-hydroquinone

2',5'-Bis-(5-N,N-di-n-butylcarbamoyl-2-methylpent-2-yl)-hydroquinone

2',5'-Bis-(5-N-eicosylcarbamoyl-2-methylpent-2-yl)-hydroquinone

2',5'-Bis-(5-N-allylcarbamoyl-2-methylpent-2-yl)-hydroquinone

2',5'-Bis-(5-N-cyclohexylcarbamoyl-2-methylpent-2-yl)-hydroquinone

2',5'-Bis-(5-N-benzylcarbamoyl-2-methylpent-2-yl)-hydroquinone

2',5'-Bis-(5-N-phenylcarbamoyl-2-methylpent-2-yl)-hydroquinone

2',5'-Bis-(5-morpholinocarbamoyl-2-methylpent-2-yl)-hydroquinone

2'-(7-Methoxycarbamoyl-2,2,4-trimethyl-hept-4-yl)-5-t-butyl-hydroquinone

Dimethyl 5-methyl-5-(2',5'-dihydroxyphenyl)-azelate

2',5'-Bis-(2,6-dimethyl-8-hydroxy-oct-2-yl)-hydroquinone 2',5'-Bis-(8-acetyloxy-2,6-dimethyl-oct-2-yl)-hydroquinone

2',5'-Bis-(2,6-dimethyl-8-propionyloxy-oct-2-yl)-hydroquinone

2',5'-Bis-(8-butyryloxy-2,6-dimethyl-oct-2-yl)-hydroquinone

2',5'-Bis-(2,6-dimethyl-8-hexanoyloxy-oct-2-yl)-hydroquinone

Diethyl-5-(4'-t-butyl-2',5'-dihydroxyphenyl)-2-ethoxycarbonyl-5-methyl-hexane-2-phosphonate

2',5'-Bis-(5,5-diethoxycarbonyl-2-methyl-pent-2-yl)-hydroquinone

2',5'-Bis-(2,6-dimethyl-8-eicosanoyloxy-oct-2-yl)-hydroquinone

2',5'-Bis-(8-crotonoyloxy-2,6-dimethyl-oct-2-yl)-hydroquinone

2',5'-Bis-(8-benzoyloxy-2,6-dimethyl-oct-2-yl)-hydroquinone

2',5'-Bis-(2,6-dimethyl-8-phenacetyloxy-oct-2-yl)-hydroquinone

2',5'-Bis-(8-cyclohexylcarbonyloxy-2,6-dimethyl-oct-2-yl)-hydroquinone

2',5'-Bis-(8-methoxy-2,6-dimethyl-oct-2-yl)-hydroquinone

2',5'-Bis-(8-n-butoxy-2,6-dimethyl-oct-2-yl)-hydroquinone

2',5'-Bis-(6-amino-2-methyl-hept-2-yl)-hydroquinone and its hydrochloride

2',5'-Bis-(6-N-methylamino-2-methyl-hept-2-yl)-hydroquinone

2',5'-Bis-(6-N,N-dimethylamino-2-methyl-hept-2-yl)-hydroquinone

2',5'-Bis-(6-N-ethylamino-2-methyl-hept-2-yl)-hydroquinone

2',5'-Bis-(6-N,N-diethylamino-2-methyl-hept-2-yl)-hydroquinone

2',5'-Bis-(6-N,N-di-n-butylamino-2-methyl-hept-2-yl)-hydroquinone

2',5'-Bis-(2-methyl-6-morpholino-hept-2-yl)-hydroquinone

2',5'-Bis-(6-acetamido-2-methyl-hept-2-yl)-hydroquinone

2'-(6-acetamido-2-methyl-hept-2-yl)-hydroquinone

2',5'-Bis-(6-hexanamido-2-methyl-hept-2-yl)-hydroquinone

2',5'-Bis-(12-Amino-2,13-dimethyl-tetradec-2-yl)-hydroquinone

2',5'-Bis-(12-amino-3,13-dimethyl-tetradec-3-yl)-hydroquinone

2',5'-Bis-(12-acetamido-2,13-dimethyl-tetradec-2-yl)-hydroquinone

2',5'-Bis-(12-acetamido-3,13-dimethyl-tetradec-3-yl)-hydroquinone

3-(2',5'-Dihydroxyphenyl)-3-methyl-butane-phosphonic acid and its sodium salt

2',5'-Bis-(2-methyl-4-phosphono-but-2-yl)-hydroquinone

Dimethyl 3-(2',5'-dihydroxyphenyl)-3-methyl-butane-phosphonate

Diethyl 3-(2',5'-dihydroxyphenyl)-3-methyl-butane-phosphonate

Di-n-butyl-3-(2',5'-dihydroxyphenyl)-3-methyl-butane-phosphonate

Dimethyl 3-(4'-t-butyl-2',5'-dihydroxyphenyl)-3-methyl-butane-phosphonate

Dimethyl 2-[4'-(1,1,3,3-tetramethylbutyl)-2',5'-dihydroxyphenyl]-3-methyl-butane phosphonate

2',5'-Bis-(2-methyl-4-di-methylphosphono-but-2-yl)-hydroquinone

2',5'-Bis-(2-methyl-4-di-ethylphosphono-but-2-yl)-hydroquinone

2',5'-Bis-(2-methyl-4-di-n-propylphosphono-but-2-yl)-hydroquinone

2'-(5-n-Hexyloxycarbonyl-2-methyl-pent-2-yl)-5'-(2-methyl-4-diethylphosphono-but-2-yl)-hydroquinone

2',5'-Bis-(2-methyl-4-di-iso-propylphosphono-but-2-yl)-hydroquinone

2',5'-Bis-(2-methyl-4-di-n-butyl-phosphono-but-2-yl)-hydroquinone

2',5'-Bis-[2-methyl-4-(di-2-ethylhexylphosphono)-but-2-yl]-hydroquinone

2',5'-Bis-(2-methyl-4-di-n-dodecylphosphono-but-2-yl)-hydroquinone

2',5'-Bis-[2-methyl-4-(2-oxo-1,3,2-dioxaphospholan-2-yl]-hydroquinone

2',5'-Bis-[2-methyl-4-(4-methyl-2-oxo-1,3,2-dioxaphospholan-but-2-yl)]-hydroquinone

2',5'-Bis-[4-(ethyl-ethylphosphino)-2-methyl-but-2-yl]-hydroquinone

2',5'-Bis-(2-methyl-3-sulpho-prop-2-yl)-hydroquinone

2-(2',5'-Dihydroxyphenyl)-2-methyl-propane sulphonamide

2-(4'-t-Butyl-2',5'-dihydroxyphenyl)-2-methyl-propane sulphonamide

N-Methyl-2-(2',5'-dihydroxyphenyl)-2-methyl-propane sulphonamide

N-Methyl-2-[2',5'-dihydroxy-4'-(1,1,3,3-tetramethylbutyl)-phenyl]-2-methyl-propane sulphonamide

N,N-Di-n-butyl-2-(2',5'-dihydroxyphenyl)-2-methyl-propane sulphonamide

N,n-Octyl-2-(2',5'-dihydroxyphenyl)-2-methyl-propane sulphonamide

N,n-Octyl-2-(4'-t-butyl-2',5'-dihydroxyphenyl)-2-methyl-propane sulphonamide

2',5'-Bis(5-cyano-2-methyl-pent-2-yl)-hydroquinone.

The present invention also provides a process for the production of compounds of formula I comprising reacting, in the presence of an acid catalyst, a hydroquinone having the formula: ##STR7## wherein R°₁ is H or a group R₁, as hereinbefore defined, with a functional alkylating agent (VI) capable of introducing a group of formula II, as hereinbefore defined.

The alkylation step is conveniently carried out at a temperature ranging from 20° C. to 150° C., but preferably in the range 80°-130° C. The acid catalyst may be a Bronsted or Lewis acid or active earth. Bronsted acids suitable for the purpose may be organic or inorganic or a partial salt thereof and may be an inorganic mineral acid such as hydrochloric, sulphuric, perchloric, and orthophosphoric acid; an alkyl, aryl or alkaryl substituted inorganic acid such as methane and ethane sulphonic acids, benzene sulphonic acid, p-toluene sulphonic acid and methane phosphonic acid; an organic acid such as dichloro acetic acid, trichloroacetic acid, and trifluoroacetic acids. Lewis acids suitable for alkylation include boron trifluoride, ferric chloride, aluminium chloride, and stannic chloride. Active earths suitable for alkylation include Fulmont®237 and Fulcat®22.

The preferred catalyst for the alkylation is p-toluene sulphonic acid. Compounds of formula I where q is 0 or 1 and p is 1 may be obtained from V where R°₁ is H or C₁ -C₈ alkyl, or residue II using from 0.1 to 1.0 moles of alkylating agent VI per mole of compound of formula V.

Alternatively compounds of formula I wherein q is 1 and R₁ is C₄ -C₈ may be prepared from compounds of formula I where q is 0 and p is 1 by alkylation of I with at least one mole of a C₄ to C₈ olefin or alcohol in the presence of an acid catalyst. Compounds of formula I where the two R groups II to be introduced are the same, may be obtained from V in which R°₁ is H using at least 2 moles of an alkylating agent VI per mole of V.

Examples of hydroquinones V include

Hydroquinone

Toluhydroquinone

2-Ethylhydroquinone

2-Propylhydroquinone

2-Isopropylhydroquinone

2-n-Butylhydroquinone

2-Isobutylhydroquinone

2-sec-Butylhydroquinone

2-t-Butylhydroquinone

2-(1,1,3,3-tetramethylbutyl)hydroquinone.

Functional alkylating agents VI which are reacted with the hydroquinone V contain a reactive centre, for example, an olefinic or hydroxy group which is eliminated, transformed or rearranged during the course of the alkylation reaction.

Examples of functional olefins suitable for the functional alkylation of compounds of formula V are:

5-Methylhex-5-enoic acid

Methyl 5-methylhex-5-enoate

Ethyl 5-methylhex-5-enoate

n-Propyl 5-methylhex-5-enoate

iso-Propyl 5-methylhex-5-enoate

n-Butyl 5-methylhex-5-enoate

iso-Butyl 5-methylhex-5-enoate

sec-Butyl 5-methylhex-5-enoate

n-Pentyl 5-methylhex-5-enoate

iso-Pentyl 5-methylhex-5-enoate

sec-Pentyl 5-methylhex-5-enoate

n-Hexyl 5-methylhex-5-enoate

Cyclohexyl 5-methylhex-5-enoate

2-Ethylhexyl 5-methylhex-5-enoate

n-octyl 5-methylhex-5-enoate

n-Dodecyl 5-methylhex-5-enoate

n-Hexadecyl 5-methylhex-5-enoate

Methyl 5,7,7-trimethyl-oct-4-enoate

1,7-Di-methoxycarbonyl-4-methyl-hept-3-ene

6-Carbomethoxy-1-methylcyclohex-1-ene

Dimethylprenylphosphonate

Diethylprenylphosphonate

Dipropylprenylphosphonate

Di-isopropylprenylphosphonate

Di-n-butylprenylphosphonate

Di-n-octylprenylphosphonate

Citronellol

Citronellyl acetate

Citronellyl methyl ether

Citronellyl butyl ether

2-Amino-6-methyl-hept-5-ene

2-Amino-6-methyl-hept-6-ene

Diethyl 2-ethoxycarbonyl-5-methyl-hex-4-ene-2-phosphonate

Ethyl 2-ethoxycarbonyl-5-methyl-hex-4-enoate.

2-Acetamido-6-methyl-hept-5-ene

2-Acetamido-6-methyl-hept-6-ene

2-Methyl-2-propene-1-sulphonic acid

2-Methyl-2-propene-1-sulphonic acid amide

N-n-Butyl-2-propene-1-sulphonic acid amide

N,N-Di-n-butyl-2-propene-sulphonic acid amide

N-n-Octyl-2-propene-1-sulphonic acid amide.

Examples of functional hydroxy compounds suitable for the functional alkylation of compounds of formula V are

2-Amino-6-hydroxy-6-methylheptane

2-Acetamido-6-hydroxy-6-methylheptane

11-Amino-2,2,12-trimethyl-tridecan-1-ol

as well as members selected from 11-amino-undecanols of the formula: ##STR8## wherein Y₁ and Y₃, independently, are H or C₁ -C₈ alkyl; Y₂ and Y₄, independently, are C₁ -C₈ alkyl; and Y₅ and Y₆, independently, are H or C₁ -C₄ alkyl.

These 11-amino-undecanols are described in more detail, together with thrie method of manufacture in German Offenlegungsschrift No. 2831299.

Examples of olefins suitable for the alkylation of compounds of formula I wherein q is 0 and p is 1 are isobutylene and diisobutylene. Examples of alcohols suitable for the alkylation of compounds of formula I wherein q is 0 and p is 1 are t-butanol and 1,1,3,3-tetramethylbutan-1-ol.

Any functional derivative of a compound of formula I may be converted to a different functional derivative. For example when Q is the acid group --CO₂ H it may be esterified with an alcohol R₄ --OH to give the corresponding ester --CO₂ R₄, or when Q is the ester group --CO₂ R₄ it may be transesterified to give a different R₄ group, or alternatively the ester group --CO₂ R₄ may be converted to an amide --CONR₄ R₅ by treatment with NHR₄ R₅, wherein R₄ and R₅ have their previous significance.

Suitable catalyst of the transesterification are e.g. p-toluene sulphonic acid and camphor sulphonic acid.

The present invention provides a valuable means of introducing a wide variety of functional alkyl residues into the hydroquinone molecule, in order to optimise the photographic effect of the said hydroquinone. For example, the polarity of and/or the ballast in the hydroquinones of formula I can be regulated and hence can provide an effective control of solubility, compatibility and mobility/immobility for photographic systems. Such qualities render the hydroquinones of formula I valuable intermediates for the preparation of more complex photographically useful compounds and make them useful as photographic stabilisers.

The hydroquinone compounds of the formula (1) as well as colour couplers can be incorporated in a known manner in photographic layers, for example in silver halide emulsions containing gelatine and/or other binders.

For example, they can be used in silver bromide, silver chloride or silver iodide emulsions or in those emulsions which contain a mixture of silver halides, such as silver bromide/iodide or silver chloride/bromide emulsions.

The emulsions can be chemically sensitised and they can also contain customary organic stabilisers and antifogging agents as well as customary plasticisers, for example glycerine. The emulsions can also be hardened with the hardeners customary for gelatine. Furthermore, the emulsions can contain customary coating assistants. The emulsions can be applied to layer supports customary for photographic recording material. Optionally, a mixture of several colloids can be used to disperse the silver halides.

The customary developer baths can be employed for developing the recording material for colour photography. These baths as a rule contain a developer substance of the p-phenylenediamine type, a development retarder, such as potassium bromide, an antioxidant, such as sodium sulfite, and a base, for example an alkali metal hydroxide or alkali metal carbonate. Furthermore, the developer baths can contain a conventional antifogging agent and complexing agents.

Corresponding application possibilities are described, for example, in U.S. Pat. Nos. 2.304.939, 2.304.940, 2.322.027, 2.284.879, 2.801.170, 2.801.171, 2.749.360 and 2.825.382.

The compounds of the invention also exhibit other advantages over known hydroquinones, for instance they have superior stability to actinic light, and may hence have a longer storage life.

The present invention is further illustrated by the following Examples, in which parts and percentages shown therein are by weight.

Example 1

110 Parts of hydroquinone, 284 parts of methyl-5-methyl-hex-5-enoate, and 10 parts of p-toluene sulphonic acid are heated on a steam-bath for 24 hours. The cooled reaction mixture partially solidified and after trituration with ether, yields after filtration, 2',5'-bis-(5-methoxycarbonyl-2-methylpent-2-yl)-hydroquinone, m.p. 150°-3° C. After crystallisation from methanol/water, the product has m.p. of 160°-2° C. with the following percentage composition by weight.

    ______________________________________                                                         Carbon                                                                               Hydrogen                                                 ______________________________________                                         Found             67.05   8.96                                                 Calculated for C.sub.22 H.sub.34 O.sub.6                                                         66.98   8.69                                                 ______________________________________                                    

Example 2

25.0 Parts of 2',5'-bis-(5-methoxycarbonyl-2-methylpent-2-yl)-hydroquinone, 250 parts of glacial acetic acid, and 125 parts of 46% aqueous hydrobromic acid are stored for 15 hours at room-temperature. At the end of this period, 2',5'-bis-(5-carboxy-2-methyl-pent-2-yl)-hydroquinone containing 1/2 molecule of acetic acid of crystallisation, is filtered off with m.p. 221°-4° C. and with the following percentage composition by weight.

    ______________________________________                                                            Carbon Hydrogen                                             ______________________________________                                         Found                63.68    8.38                                             Calculated for C.sub.20 H.sub.30 O.sub.6 (CH.sub.3 CO.sub.2 H)1/2                                   63.62    8.14                                             ______________________________________                                    

5.0 Parts of 2',5'-bis-(5-carboxy-2-methylpent-2-yl)-hydroquinone, 100 parts of absolute ethanol, and 1.0 parts of 98% sulphuric acid are refluxed for 16 hours. The solution is then stripped down under reduced pressure, the residue taken up in ether, and washed with sodium bicarbonate solution. The ethereal solution after being concentrated and diluted with 40°-60° C. petroleum ether yields 2',5'-bis-(5-ethoxycarbonyl-2-methylpent-2-yl)-hydroquinone, m.p. 146°-9° C. with the following percentage composition by weight.

    ______________________________________                                                         Carbon Hydrogen                                                ______________________________________                                         Found             68.62    9.43                                                Calculated for C.sub.24 H.sub.38 O.sub.6                                                         68.22    9.06                                                ______________________________________                                    

Examples 3 to 20 in the following table further exemplify esters similarly prepared from 2',5'-bis-(5-carboxy-2-methylpent-2-yl)-hydroquinone, according to the procedure described in Example 2.

    ______________________________________                                                                  Found and                                             Di-ester of 2',5'-bis-   Required %                                            (5-carboxy-2-methyl-     Composition                                           Exam- pent-2-yl)-   m.p.    Molecular    Hydro-                                ple   hydroquinone  °C.                                                                             Formula                                                                               Carbon                                                                               gen                                   ______________________________________                                         3     n-propyl      134-6   C.sub.26 H.sub.42 O.sub.6                                                             69.08 9.29                                                                     69.30 9.36                                  4     iso-propyl    140-3   C.sub.26 H.sub.42 O.sub.6                                                             68.57 9.70                                                                     69.30 9.36                                  5     n-butyl       105-8   C.sub.28 H.sub.46 O.sub.6                                                             70.54 9.97                                                                     70.26 9.69                                  6     iso-butyl     135-8   C.sub.28 H.sub.46 O.sub.6                                                             70.57 9.97                                                                     70.26 9.96                                  7     n-pentyl      80-4    C.sub.30 H.sub.50 O.sub.6                                                             71.88 11.10                                                                    71.11 9.95                                  8     iso-pentyl    94-7    C.sub.30 H.sub.50 O.sub.6                                                             70.65 9.97                                                                     71.11 9.95                                  9     n-hexyl       85-7    C.sub.32 H.sub.54 O.sub.6                                                             71.77 10.23                                                                    71.87 10.18                                 10    cyclo-hexyl   176-80  C.sub.32 H.sub.50 O.sub.6                                                             72.61 9.74                                                                     72.42 9.50                                  11    n-heptyl      87-8    C.sub.34 H.sub.58 O.sub.6                                                             72.75 10.48                                                                    72.56 10.39                                 12    2-ethylhexyl  60-2    C.sub.36 H.sub.62 O.sub.6                                                             73.15 10.76                                                                    73.18 10.58                                 13    n-octyl        77-80  C.sub.36 H.sub.62 O.sub.6                                                             73.39 10.71                                                                    73.18 10.58                                 14    n-dodecyl     77-9    C.sub.44 H.sub.78 O.sub.6                                                             75.46 10.91                                                                    75.21 11.11                                 15    n-hexadecyl   81-4    C.sub.52 H.sub.94 O.sub.6                                                             76.48 11.59                                                                    76.65 11.54                                 16    allyl         136-9   C.sub.26 H.sub.38 O.sub.6                                                             70.14 8.61                                                                     69.93 8.58                                  17    tetrahydrofurfuryl                                                                           112-4   C.sub.30 H.sub.46 O.sub.8                                                             67.23 8.90                                                                     67.39 8.67                                  18    2-n-butoxyethyl                                                                              87-9    C.sub.32 H.sub.54 O.sub.8                                                             67.70 9.88                                                                     67.81 9.60                                  19    2-phenoxyethyl                                                                               140-3   C.sub.36 H.sub.46 O.sub.8                                                             70.63 7.98                                                                     71.26 7.64                                  20    benzyl        139-41  C.sub.34 H.sub.42 O.sub.6                                                             74.57 7.89                                                                     74.70 7.74                                  ______________________________________                                    

Example 21

8.0 Parts of 2',5'-bis-(5-methoxycarbonyl-2-methyl-pent-2-yl)-hydroquinone, 100 parts of furfuryl alcohol and 1.0 parts of sodium methoxide are heated on a steam bath for 24 hours. The cooled reaction mixture is diluted with ether and washed with water. After removing the ether and excess furfuryl alcohol, the residue is triturated with 40°-60° petroleum ether containing ether to yield 2',5'-bis-(5-furfuryloxycarbonyl-2-methylpent-2-yl)-hydroquinone, m.p. 139°-42° C. Crystallisation from methanol containing 5% water gives crystals m.p. 140°-3° C. with the following percentage composition by weight.

    ______________________________________                                                          Carbon                                                                               Hydrogen                                                ______________________________________                                         Found              67.45   7.50                                                Calculated for C.sub.30 H.sub.38 O.sub.8                                                          68.42   7.27                                                ______________________________________                                    

Example 22

5.5 Parts of hydroquinone, 21.2 parts of n-hexyl 5-methyl-hex-5-enoate, and 1.0 parts of p-toluene sulphonic acid are heated on a steam bath for 4 days. The cooled reaction mixture is taken up in ether, washd with 10% sodium hydroxide solution and then with water, until neutral. After stripping, the residual oil which partially solidified, is triturated with 40°-60° petroleum ether and gave 2',5'-bis-(5-n-hexyloxycarbonyl-2-methyl-pent-2-yl)-hydroquinone m.p. 77°-8° C. A further crystallisation from 60°-80° C. petroleum ether gives material m.p. 83°-6° C. identical with that obtained in Example 9.

Example 23

2.0 Parts of bis-2',5'-(5-methoxycarbonyl-2-methyl-pent-2-yl)-hydroquinone, and 15.0 parts of n-butylamine are refluxed for 18 hours and the excess butylamine then removed under reduced pressure. The residue after treatment with ether gives 2',5'-bis-(5-N-n-butylcarbamoyl-2-methyl-pent-2-yl)-hydroquinone, which after crystallisation from ethanol, has m.p. 198°-200° C. and the following percentage composition by weight.

    ______________________________________                                                       Carbon Hydrogen  Nitrogen                                        ______________________________________                                         Found           70.39    10.21     5.83                                        Calculated for C.sub.28 H.sub.48 N.sub.2 O.sub.4                                               70.55    10.15     5.88                                        ______________________________________                                    

Example 24

2.0 Parts of bis-2',5'-(5-methoxycarbonyl-2-methyl-pent-2-yl)-hydroquinone, and 10.0 parts of di-n-butylamine are sealed into a glass Carius tube and heated at 160° C. for 72 hours. After removing the excess di-butylamine under reduced pressure, the solid residue is washed with ether and gives bis-2',5'-(5-di-N,N-n-butyl carbamoyl-2-methyl-pent-2-yl)-hydroquinone, m.p. 175°-9° C. Two further crystallisations from ethanol gives product m.p. 190°-2° C. with the following percentage composition by weight.

    ______________________________________                                                       Carbon Hydrogen  Nitrogen                                        ______________________________________                                         Found           73.06    11.35     4.83                                        Calculated for C.sub.36 H.sub.64 N.sub.2 O.sub.4                                               73.42    10.95     4.76                                        ______________________________________                                    

Example 25

5.5 Parts of hydroquinone, 19.8 parts of citronellyl acetate and 1.0 parts of p-toluene sulphonic acid are heated on a steam-bath for 24 hours. The reaction mixture is then taken up in ether, washed with 10% sodium hydroxide solution, water, and evaporated to give a residue. This residue is distilled using a short-path distillation at 0.13 mb and gives 2',5'-bis-(8-acetoxy-2,6-dimethyl-oct-2-yl)-hydroquinone as a viscous amber oil which slowly solidified. Crystallisation from 60°-80° petroleum-ether gives product m.p. 60°-2° C. and the following percentage composition by weight.

    ______________________________________                                                          Carbon                                                                               Hydrogen                                                ______________________________________                                         Found              73.18   10.58                                               Calculated for C.sub.36 H.sub.62 O.sub.6                                                          73.15   10.76                                               ______________________________________                                    

Example 26

5.5 Parts of hydroquinone, 15.4 parts of 1-methyl-4-methoxycarbonylcyclohex-1-ene, and 0.5 parts of p-toluene sulphonic acid are heated on a steam-bath for 3 days. The reaction mixture after dilution with ether gives a stereoisomeric mixture of 2',5'-bis-(4-methoxycarbonyl-1-methyl-cyclohex-1-yl)-hydroquinones m.p. 266°-83° C. Crystallisation from dimethylformamide and water gives product m.p. 268°-87° C. containing 1 mole of dimethylformamide of crystallisation, and the following percentage composition by weight.

    ______________________________________                                                     Carbon  Hydrogen  Nitrogen                                         ______________________________________                                         Found         65.65     8.32      2.28                                         Calculated for                                                                               65.96     8.41      2.85                                         C.sub.24 H.sub.34 O.sub.6.C.sub.3 H.sub.7 NO                                   ______________________________________                                    

Example 27

12.4 Parts of toluhydroquinone, 21.2 parts of n-hexyl 5-methyl-hex-5-enoate, and 0.3 parts of p-toluene sulphonic acid are reacted and worked up as described in Example 25. Distillation under pressure gives a fraction b₀.1 217°-26° C. which analysis showed to contain 14% of n-hexyl 5-(2',5'-dihydroxy-3'-methylphenyl)-5-methylhexanoate and 82% of n-hexyl-5-(2',5'-dihydroxy-4'-methylphenyl)-5-methyl-hexanoate and which has the following percentage composition by weight:

    ______________________________________                                                          Carbon                                                                               Hydrogen                                                ______________________________________                                         Found              71.24   10.11                                               Calculated for C.sub.20 H.sub.32 O.sub.4                                                          71.39   9.59                                                ______________________________________                                    

Example 28

16.6 Parts of 2-t-butylhydroquinone, 14.2 parts of methyl 5-methyl-hex-5-enoate and 0.5 parts of p-toluene sulphonic acid are reacted and worked up as described for Example 25. Distillation gives methyl 5-(4'-t-butyl-2',5'-dihydroxyphenyl)-5-methylhexanoate, b₀.3 186°-210° C. This fraction, after crystallisation from 40°-60° petroleum ether, has m.p. 136°-9° C. and the following percentage composition by weight.

    ______________________________________                                                          Carbon                                                                               Hydrogen                                                ______________________________________                                         Found              70.39   9.39                                                Calculated for C.sub.18 H.sub.28 O.sub.4                                                          70.10   9.15                                                ______________________________________                                    

Example 29

The methyl ester of Example 28, 5.0 parts, is converted to the corresponding n-hexyl ester after reaction with 20 parts n-hexanol and 0.25 parts of sodium methoxide in a sealed glass tube for 7 days. The reaction mixture is diluted with ether, washed with dilute hydrochloric acid, then water, and stripped for ether and excess hexanol under reduced pressure to yield a residue. Short-path distillation of this residue at 0.4 mb. gives n-hexyl 5-(4'-t-butyl-2',5'-dihydroxyphenyl)-5-methyl-hexanoate as an amber oil with the following percentage composition by weight.

    ______________________________________                                                          Carbon                                                                               Hydrogen                                                ______________________________________                                         Found              72.33   10.26                                               Calculated for C.sub.23 H.sub.38 O.sub.4                                                          72.98   10.12                                               ______________________________________                                    

Example 30

Similarly by the procedure of Example 29 from n-dodecanol and the methyl ester of Example 28, is prepared n-dodecyl 5-(4'-t-butyl-2',5'-dihydroxyphenyl)-5-hexanoate with the following percentage composition by weight.

    ______________________________________                                                          Carbon                                                                               Hydrogen                                                ______________________________________                                         Found              75.49   11.01                                               Calculated for C.sub.29 H.sub.50 O.sub.4                                                          75.28   10.89                                               ______________________________________                                    

Example 31

83 Parts of 2-t-butylhydroquinone, 17.8 parts of dimethylprenylphosphonate, and 5.0 parts of Fulmont® 237 are stirred at 130° C. for 24 hours. The cooled reaction mixture is diluted with ether, filtered free of catalyst, and the ether solution washed firstly with 10% sodium hydroxide solution to remove t-butyl hydroquinone and then with water.

The ethereal extract is then evaporated and the residue diluted with 40°-60° petroleum ether containing ether. After being set aside at 0° C. there is obtained a light brown solid, m.p. 153°-65° C. which following a further crystallisation from ether containing a little acetone, give dimethyl 3-(4'-t-butyl-2',5'-dihydroxyphenyl)-3-methylbutane-phosphonate with m.p. 193°-5° C. with the following percentage composition by weight.

    ______________________________________                                                      Carbon  Hydrogen  Phosphorus                                      ______________________________________                                         Found          59.99     8.38      8.62                                        Calculated for C.sub.17 H.sub.29 O.sub.5 P                                                    59.29     8.49      8.99                                        ______________________________________                                    

Example 32

83 Parts of t-butylhydroquinone, 19.8 parts of methyl 5,7,7-trimethyloct-4-enoate, and 5.0 parts of Fulmont® 237 are reacted and worked up as described in Example 31. The product is distilled using a short-path rotary distillation at 0.13 mb and gives, after removing lower boilers, methyl 5-(4'-t-butyl-2',5'-dihydroxyphenol)-5,7,7-trimethyl-octanoate with the following percentage composition by weight.

    ______________________________________                                                          Carbon                                                                               Hydrogen                                                ______________________________________                                         Found              72.72   9.32                                                Calculated for C.sub.22 H.sub.36 O.sub.4                                                          72.49   9.95                                                ______________________________________                                    

Example 33

The mother liquors from the preparation of 2',5'-bis-(5-methoxycarbonyl-2-methylpent-2-yl)-hydroquinone, in Example 1, are concentrated and then distilled. A fraction b₀.5 160°-240° C. was collected and diluted with 40°-60° petroleum ether. From this solution there crystallises 2'-(5-methoxycarbonyl-2-methylpent-2-yl)-hydroquinone, m.p. 102°-4° C. with the following percentage composition by weight.

    ______________________________________                                                          Carbon                                                                               Hydrogen                                                ______________________________________                                         Found              66.65   7.99                                                Calculated for C.sub.14 H.sub.20 O.sub.4                                                          66.45   8.45                                                ______________________________________                                    

Example 34

5.5 Parts of hydroquinone, 22.8 parts of 1,7-di-methoxycarbonyl-4-methylhept-3-ene and 1.0 parts of p-toluene sulphonic acid, are heated on a steam-bath for 3 days. After dilution with ether the reaction mixture is washed with sodium bicarbonate solution, water, evaporated and distilled to give dimethyl 5-methyl-5-(2',5'-dihydroxyphenyl)-azelate, b₀.1 260°-9° C. with the following percentage composition by weight.

    ______________________________________                                                          Carbon                                                                               Hydrogen                                                ______________________________________                                         Found              64.34   7.92                                                Calculated for C.sub.18 H.sub.26 O.sub.6                                                          63.89   7.74                                                ______________________________________                                    

EXAMPLE 35

41.4 Parts of 2-t-butylhydroquinone, 15.3 parts of diethyl 2-ethoxycarbonyl-5-methyl-hex-4-ene-2-phosphonate, and 5.0 parts of Fulmont® 237 are stirred at 130° C. for 24 hours. The cooled reaction is diluted with ether, washed with 10% sodium hydroxide solution and then with water. After stripping off the ether, the residual oil is distilled and gives a fraction b₀.4 89°-156° C. and a residue. This residue is chromatographed on a column established from 150 parts silica, and an initial solvent mixture comprising petroleum-ether (b.p. 40°-60° C.) and 5% ethylacetate. Column elution is carried out by increasing the percentage of ether, and ultimately with 50% ether present, diethyl 5-(4'-t-butyl-2',5'-dihydroxyphenyl)-2-ethoxycarbonyl-5-methyl-hexane-2-phosphonate is obtained as a viscous oil with the following percentage composition by weight.

    ______________________________________                                                      Carbon Hydrogen  Phosphorus                                       ______________________________________                                         Found          61.16    8.52      6.61                                         Calculated for C.sub.24 H.sub.41 O.sub.7 P                                                    60.99    8.74      6.55                                         ______________________________________                                    

Example 36 2.2 Parts of hydroquinone, 8.5 parts of n-butyl citronellyl ether, and 0.5 parts of p-toluene sulphonic acid are heated on a steam-bath for 3 days. The work up follows Example 25 and, by short path distillation at 0.5 mb, there is obtained 2',5'-bis-(8-n-butoxy-2,6-dimethyl-oct-2-yl)-hydroquinone with m.p. 86°-9° C. and the following percentage composition by weight.

    ______________________________________                                                          Carbon                                                                               Hydrogen                                                ______________________________________                                         Found              76.43   11.88                                               Calculated for C.sub.34 H.sub.62 O.sub.4                                                          76.35   11.68                                               ______________________________________                                    

Example 37

Similarly obtained by the procedure of Example 36, using 6.2 parts of citronellol in place of the n-butylcitronellyl ether is obtained 2',5'-bis-(2,6-dimethyl-8-hydroxyoct-2-yl)-hydroquinone as a viscous oil with the following percentage composition. by weight

    ______________________________________                                                          Carbon                                                                               Hydrogen                                                ______________________________________                                         Found              74.18   11.07                                               Calculated for C.sub.26 H.sub.46 O.sub.4                                                          73.89   10.97                                               ______________________________________                                    

Example 38

By the procedure of Example 2, 4.8 parts of 2',5'-bis-(5-carboxy-2-methyl-pent-2-yl)-hydroquinone, 50 parts of tetrahydropyran-2-methanol, and 1.0 parts of p-toluene sulphonic acid are used to prepare 2,'5'-bis-(5-tetrahydropyran-4-yloxycarbonyl-2-methyl-pent-2-yl)-hydroquinone with m.p. 155°-8° C. and the following percentage composition by weight.

    ______________________________________                                                          Carbon                                                                               Hydrogen                                                ______________________________________                                         Found              68.62   9.05                                                Calculated for C.sub.32 H.sub.50 O.sub.8                                                          68.30   8.96                                                ______________________________________                                    

Example 39

5.0 Parts of 2',5'-bis-(5-carboxy-2-methyl-pent-2-yl)-hydroquinone, 50 parts of commercial iso-octanol (mixed isomers, supplied by ICI Ltd.) and 1.0 parts of p-toluene sulphonic acid are reacted and worked up according to the procedure of Example 2. Short-path distillation at 0.5 mb using an oven temperature of 240° C. gave 2',5'-bis-(2-methyl-5-iso-octyloxycarbonyl-pent-2-yl)-hydroquinone as a viscous oil with the following percentage composition by weight.

    ______________________________________                                                          Carbon                                                                               Hydrogen                                                ______________________________________                                         Found              73.94   10.87                                               Calculated for C.sub.36 H.sub.62 O.sub.6                                                          73.18   10.58                                               ______________________________________                                    

Example 40

1.1 Parts of hydroquinone, 4.5 parts of ethyl 2-ethoxycarbonyl-5-methyl-hex-4-enoate, and 0.5 parts of p-toluene sulphonic acid, are heated on a steam-bath for 3 days. The reaction mixture is then diluted with ether, washed with 10% sodium hydroxide solution, water and evaporated. Short-path rotary distillation at 0.7 mb removed lower-boilers at an oven temperature of 120° C. The residue is crystallised from petroleum-ether (b.p. 40°-60° C.) containing 5% ethyl acetate and gives 2',5'-bis-(5,5-diethoxycarbonyl-2-methyl-pent-2-yl)-hydroquinone with m.p. 157°-60° C. and the following percentage composition by weight.

    ______________________________________                                                          Carbon                                                                               Hydrogen                                                ______________________________________                                         Found              63.90   8.28                                                Calculated for C.sub.30 H.sub.45 O.sub.10                                                         63.59   8.18                                                ______________________________________                                    

Examples of the Use of the new Hydroquinones of Formula I as stabilisers in colour photographic material Use Example 1

0.05 mMol of the magenta coupler of the following formula ##STR9## and 0.025 mMol of the compound of formula I are dissolved in 2.0 ml of tricresylphosphate/ethyl acetate (0.75 g./100 ml). 7.0 ml of a 6% gelatin solution, 1.0 ml of a 0.8% solution of the wetting agent of the formula ##STR10## are put into water, then emulsified for 5 minutes by means of a 100-Watt ultra-sonic appliance. 2.5 ml of coupler-additive emulsion, freshly treated in the ultra-sonic appliance, 2.0 ml of silver bromide emulsion with a content of 0.6% silver, 0.7 ml of a 1% aqueous solution of the curing agent with the following formula ##STR11## and 2.8 ml of water are mixed together, set to a pH value of 6.5, and at 40° C. poured onto a polyethylene paper measuring 14×18 cm. After the coating has hardened at 10° C., the poured-on mixture is dried at room-temperature.

Processing

The samples of the coated paper obtained are exposed to light of 500 Lux under a step-wedge for 6 seconds and then processed as follows at 32.8° C. (±0.3° C.):

    ______________________________________                                         1.      Developer bath     3.5 minutes                                         2.      Bleaching fixing bath                                                                             1.5 minutes                                         3.      Washing            3.0 minutes                                         4.      Drying             1.0 minutes                                         ______________________________________                                    

The developer bath has the following composition: 4-Amino-3-methyl-N-ethyl-N-[β-(methyl-sulphonamido)ethyl]-aniline

    ______________________________________                                         11/2 H.sub.2 SO.sub.4.H.sub.2 O                                                                     4.85   (g/liter)                                          Potassium bromide    0.6                                                       Potassium carbonate  32.0                                                      Lithium sulphate     1.8                                                       Potassium sulphite   2.0                                                       Hydroxylaminesulphite                                                                               3.9                                                       Ethyleneglycol       21.3                                                      Benzyl alcohol       15.1                                                      Water                to     1 liter                                            ______________________________________                                    

The pH value is 10.1 The bleaching fixing bath used is a conventional bath, with e.g. the following composition:

    ______________________________________                                         Ammoniumthiosulphate (80% solution)                                                                   200    (g/liter)                                        Sodium sulphite (anhydrous)                                                                           15                                                      Sodium carbonate (anhydrous)                                                                          2.5                                                     Ethylenediamine tetra-acetic acid,                                                                    2                                                       sodium salt                                                                    Ethylenediamine tetra-acetic acid                                                                     50                                                      sodium-iron-(III)-salt                                                         Water                  to     1 liter                                          ______________________________________                                    

After washing and drying, clear, sharp magenta wedges are obtained with absorption maximum at 537 nm and maximum densities of 2.28.

A step-wedge obtained in this way is exposed to light in the Atlas apparatus (2500-W lamp) with 42 kJ/cm² through an ultra-violet filter (Kodak filter 2C). For comparison, a step-wedge prepared analogously, which contains no compound according to the invention. In all cases the residual optical density (OD) was measured in % of the initial density (initial density 1). Table 1 contains the results.

                  TABLE 1                                                          ______________________________________                                         Light Stabilising Effect of Compounds of Formula I                             Hydroquinone  % OD (with UV filter; 42 kJ/cm.sup.2)                            ______________________________________                                         Without light stabiliser                                                                     37                                                               Product of Example 9                                                                         80                                                               Product of Example 11                                                                        84                                                               Product of Example 12                                                                        87                                                               Product of Example 14                                                                        81                                                               Product of Example 15                                                                        85                                                               Product of Example 18                                                                        78                                                               Product of Example 25                                                                        76                                                               ______________________________________                                    

Compared with the emulsion without stabiliser, emulsions containing the compounds of formula I are more stable to light.

Use Example 2

In an analogous series of experiments to those described in Use Example 1, further compounds of formula I were evaluated and the results are listed in Table 2.

                  TABLE 2                                                          ______________________________________                                         Light Stabilising Effect of Compounds of Formula I                             Hydroquinone  % OD (with UV filter; 42 kJ/cm.sup.2)                            ______________________________________                                         Without light stabiliser                                                                     41                                                               Product of Example 19                                                                        85                                                               Product of Example 17                                                                        88                                                               Product of Example 29                                                                        87                                                               Product of Example 30                                                                        91                                                               Product of Example 32                                                                        78                                                               Product of Example 21                                                                        58                                                               Product of Example 24                                                                        55                                                               ______________________________________                                    

Compared with the emulsion without stabiliser, emulsions containing compounds of formula I are more stable to light.

Use Example 3

Emulsion prepared according to Example 1, but containing 0.05 mMol of the Magenta coupler of the following formula: ##STR12## instead of the magenta coupler of the following formula: ##STR13## containing 0.025 mMol of Example 9 was processed analogously and exposed to 42 kJ/cm² in the Atlas apparatus. The increase in density measured at a wavelength of 436 (yellowing) was measured. The following values were obtained.

                  TABLE 3                                                          ______________________________________                                         Light Stabilising Effect of Product of Example 9                                              Increase 100 D.sub.436 after 42 kJ/cm.sup.2                     Hydroquinone   in the Atlas apparatus                                          ______________________________________                                         Without light stabiliser                                                                      10                                                              Product of Example 9                                                                          -1                                                              ______________________________________                                    

Compared with the emulsion without stabiliser, emulsions containing the product of Example 9 show no increase in density 436.

Example 41

5.0 Parts of 2',5'-bis-(5-carboxy-2-methyl-pent-2-yl)-hydroquinone, 50 parts of an amyl/isobutyl alcohol mixture (supplied by Hoechst AG) and 0.5 parts of p-toluene sulphonic acid were reacted and worked up according to the procedure of Example 2. The ethereal solution after being concentrated was then diluted with 60°-80° petroleum-ether to yield a mixture of the amyl and isobutyl esters of the starting material acid with m.p. 106°-20° C. and the following percentage composition by weight.

    ______________________________________                                                          Carbon                                                                               Hydrogen                                                ______________________________________                                         Found              70.82   9.82                                                Calculated for C.sub.29 H.sub.48 O.sub.6                                                          70.70   9.82                                                ______________________________________                                    

Example 42

By the procedure of Example 39, 50 parts of Epal 108 (n-decanol/octanol mixture supplied by the Ethyl Corporation) was used to esterify 5.0 parts of 2',5'-bis-(5-carboxy-2-methyl-pent-2-yl)-hydroxquinone. Short-path distillation gave the ester product as a viscous oil with the following percentage composition by weight.

    ______________________________________                                                          Carbon                                                                               Hydrogen                                                ______________________________________                                         Found              74.49   11.00                                               Calculated for C.sub.38 H.sub.66 O.sub.6                                                          73.74   10.75                                               ______________________________________                                    

Use Example 4

In an analogous series of experiments to those described in Use Example 1, further compounds of formula 1 were evaluated and the results are listed in Table 4.

                  TABLE 4                                                          ______________________________________                                         Hydroquinone  % OD (with UV filter; 42 kJ/cm.sup.2)                            ______________________________________                                         Without light stabiliser                                                                     45                                                               Product of Example 16                                                                        87                                                               Product of Example 27                                                                        80                                                               Product of Example 41                                                                        90                                                               Product of Example 42                                                                        90                                                               ______________________________________                                    

Use Example 5

In an analogous series of experiments to those described in Use Example 1, further compounds of formula 1 were evaluated and the results are listed in Table 5.

                  TABLE 5                                                          ______________________________________                                         Hydroquinone   % OD (with UV filter; 21 kJ/cm.sup.2                            ______________________________________                                         Without light stabiliser                                                                      84                                                              Product of Example 35                                                                         94                                                              Product of Example 36                                                                         97                                                              Product of Example 37                                                                         93                                                              Product of Example 38                                                                         96                                                              Product of Example 39                                                                         98                                                              Product of Example 40                                                                         96                                                              Product of Example 41                                                                         98                                                              ______________________________________                                     

I claim:
 1. A hydroquinone compound of the formula: ##STR14## wherein p is 1 or 2 and q is 0 or 1, provided that p+q is 1 or 2; R is a group of the formula ##STR15## wherein Q is a number selected from the groups: (i) --OX wherein X is R₅ or COR₇ wherein R₅ is hydrogen or a straight or branched chain alkyl group having from 1 to 20 carbon atoms,R₇ is hydrogen or a straight or branched chain alkyl group having from 1 to 20 carbon atoms, a straight or branched chain alkenyl group having from 3 to 20 carbon atoms, a cycloalkyl group having from 3 to 12 carbon atoms, an aralkyl group having from 7 to 13 carbon atoms or an unsubstituted or mono- or di-C₁ -C₄ -alkyl substituted aryl group having from 6 to 10 carbon atoms, and(ii) --PO(OR₁₀)((O)_(x) R₁₁) wherein X is 1, R₁₀ and R₁₁ are the same or different and each is hydrogen or a straight or branched chain alkyl group having from 1 to 20 carbon atoms, n is an integer from 2 to 20: k is 1 or 2; R₂ and R₃ are the same or different and each is a straight or branched chain alkyl group having from 1 to 5 carbon atoms; and R₁ is a straight or branched chain alkyl group having from 1 to 8 carbon atoms, or a group of formula II as hereinbefore defined and, when R₁ is a group of formula II, then R₁ and R may be the same or different; or a salt thereof with an organic or inorganic acid or base.
 2. A compound according to claim 1 wherein p, q, R, Q, R₁, R₂, R₃, R₅, R₇, p, k and n are as defined in claim 9; and R₁₀ and R₁₁, when x is 1, are the same or different and each is hydrogen or a straight or branched chain alkyl group having from 1 to 20 carbon atoms; or a salt thereof.
 3. A compound according to claim 1 wherein the groups R and R₁ are bonded in the 2- or 5-positions, respectively; or a salt thereof.
 4. A compound according to claim 1 of the formula: ##STR16## wherein R₂, R₃, Q, n and k are as defined in claim 1; and R₁ is a group of formula II as defined in claim 1, or is a group of formula: ##STR17## or a salt thereof.
 5. A compound of formula III according to claim 4 whereinR₁ is as defined in claim 4; Q is --OR₅ wherein R₅ is hydrogen or a straight or branched chain alkyl group having from 1 to 20 carbon atoms; and R₂ and R₃, independently, are methyl, ethyl, n-propyl, isopropyl or neopentyl; or a salt thereof.
 6. A compound of formula III according to claim 5 whereink is 1; R₁ is a group of the formula ##STR18## or of the formula ##STR19## Q is --OR₅ ; n is an integer from 2 to 10, and R₂ and R₃, independently, are methyl, ethyl or neopentyl; or a salt thereof.
 7. A compound of formula III according to claim 6 whereink is 1; R₁ is a group of the formula ##STR20## or of the formula ##STR21## Q is --OR₅ wherein R₅ is hydrogen or C₁ -C₁₅ alkyl; n is an integer from 2 to 10; and R₂ and R₃, independently, are methyl, ethyl or neopentyl; or a salt thereof.
 8. The compound 2,5-bis-(8-n-butoxy-2,6-dimethyl)-oct-2-yl)-hydroquinone. 